RRC-B Field Operations Core The allocation of resources to this Core will produce economies of scale and reduce duplication of effort among OAIC studies. Standard Operating Procedures already established will be modified to meet specific IDS needs. The aims and tasks of the Field Operations Core (FC) are: 1. To conduct centralized participant identification, recruitment, enrollment, surveillance and tracking for the IDS and pilot studies. 2. To develop and pretest, in collaboration with the OAIC investigators and Design, Analysis and Data Management Core, all data collection methods to be used in the IDS and pilot studies. 3. To administer screening, baseline and follow-up assessments for the IDS and pilot studies implemented through the Yale OAIC. 4. To ensure that theIDS and pilot studies conducted through the Yale OAIC use comparable data collection instruments and methods whenever feasible. 5. To hire, training and supervise research associates, interviewers, assessors and support staff who will recruit and enroll participants; obtain informed consent; perform screening , baseline and follow-up assessments; conduct ongoing surveillance; and prepare materials for data entry. 6. To maintain and enhance relationships between Yale OAIC investigators and the hospitals, clinics, home care agencies, nursing homes, elderly housing and the greater New Haven area communities. 7. To mentor junior faculty regarding the field operations necessary to effectively and efficiently carry out clinical trials and pilot studies.